1. Field of the Invention
The present invention relates to a process cartridge detachable from an electrophotographic image forming apparatus. The process cartridge is a cartridge having an image bearing member, and at least a charging unit and a developing unit formed integrally as a cartridge and detachable from a main body of an image forming apparatus. Here, the image forming apparatus is an apparatus for forming an image on a recording medium using an electrophotographic forming process, and includes, for example, an electrophotographic copying machine, an electrophotographic printer such as a light emitting diode (LED) printer and a laser beam printer, and an electrophotographic facsimile apparatus.
2. Description of the Related Art
Conventionally, in the image forming apparatus using the electrophotographic image forming apparatus, a cartridge method has been adapted. In the cartridge method, the image bearing member and a process unit, which acts on the image bearing member, are integrally formed into a cartridge and the cartridge is detachable from the image forming apparatus. According to the cartridge method, a user can perform maintenance of an apparatus by oneself without depending on a serviceman, so that operability of the apparatus can be remarkably increased. Thus, the cartridge method is widely used in the image forming apparatus.
According to the cartridge method, the operability is increased, and it becomes possible for a user to easily perform the maintenance of the electrophotographic image forming apparatus by oneself. Thus, the cartridge method is widely used in the image forming apparatus.
In many cartridges, a detachable protection member is adopted for protecting a surface of a photosensitive drum from light, dust, fluff, and scratches at a time of shipping (for example, refer to FIG. 4 in Japanese Application Laid-Open No. 9-127851). A user detaches the protection member before mounting the cartridge to an image forming apparatus, and mounts the cartridge to an image forming apparatus as it is.
Further, as a countermeasure of toner leak at a time of shipping, Japanese Patent Laid-Open No. 2000-19839 discusses, in FIG. 6, a configuration in which a sealing member is adhered to the protection member itself, and this configuration is adopted in some cartridges.
Further, recently, for increasing operability, a configuration for eliminating a toner seal, which closes an opening for supplying a toner to the developing unit has been adopted. This configuration is realized by removing the seal at a time of exchanging a cartridge. To realize this configuration, metal parts are added for increasing strength of a seating surface to which a flexible sheet member is fixed. In this case, the flexible sheet acts to prevent toner leak at a space between a development roller and a development case frame member.
The protection members like the conventional examples protect only the surface of the photosensitive drum, and there is a possibility that toner leak and toner dispersion come about near the development roller by a physical distribution at a time of shipping.
In a toner seal-less configuration, countermeasures against the toner leak and the toner dispersion is needed only at a time of the physical distribution. Thus, implementing the countermeasure by adding metal parts like the conventional example leads to a cost rise and may become a superfluous measure. Further, like the configuration discussed in Japanese Patent Laid-Open No. 2000-19839, a configuration of providing the sealing member to the protection member also causes a cost rise.
Further, when a process cartridge, which has reached the end of useful life, is collected, it is necessary to attach again the protection member to the process cartridge, for preventing the waste toner leak from a waste toner chamber.